* = After 5-7 days, increase tolerance to 27° F even if there is no change in appearance.** = After 5-7 days, increase tolerance to 29.5°-30° F even if there is no change in appearance.

Fall Cranberry Frost Tolerances

Maturity Level

Early Black

Howes

Stevens

Ben Lear

Deep blush on exposed surface

27° F

27° F

27° F

27° F

Deep blush

26° F

26° F

26° F

26° F

Red

25° F

25° F

25° F

25° F

Deep red

23° F

23° F

23° F

24° F

Maroon (1-2 weeks later)

23° F

20° F

22° F

24° F

Over-ripe (end of October)

23° F

23° F **

23° F **

24° F

** = loss of tolerance when over-ripe

Please note that each variety will reach a given stage on a different date. Generally, Early Black and Ben Lear will both color early and Howes and Stevens will color later. This tolerance chart is based on color development, which is used as a visual guide to ripening, a chemical and physiological process. In some years, lower tolerances were found. However, we cannot predict when this will occur so conservative figures are presented here. In each of three years, cranberries showed tolerances at least as low as these for the stages listed.